<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
       .parent{
        border: 2px solid #333;
        width: 100px;
        height: 100px;
       }
       .test{
        width: 40px;
        height: 40px;
        background: pink;
        margin-top: 30%;
       }
    </style>
</head>
<body>
    <div class="parent">
        <div class="test"></div>
    </div>
</body>
</html>
